[Federal Register Volume 89, Number 80 (Wednesday, April 24, 2024)]
[Rules and Regulations]
[Pages 31078-31090]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-08453]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 34

[Docket No.: FAA-2023-2434; Amdt. No. 34-7]
RIN 2120-AL83


Control of Non-Volatile Particulate Matter From Aircraft Engines: 
Emission Standards and Test Procedures

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: This action adopts standards for measuring non-volatile 
particulate matter (nvPM) exhaust emissions from aircraft engines. With 
this rulemaking, the FAA implements the nvPM emissions standards 
adopted by the Environmental Protection Agency (EPA), allowing 
manufacturers to certificate engines to the new nvPM emissions 
standards in the United States, and fulfilling the statutory 
obligations of the FAA under the Clean Air Act.

DATES: This rule is effective May 24, 2024.
    The incorporation by reference of a certain publication listed in 
this rule is approved by the Director of the Federal Register as of May 
24, 2024. The incorporation by reference of a certain other publication 
listed in this rule was approved by the Director of the Federal 
Register as of December 31, 2012 (77 FR 76842).
    Comments on this rule must be received by June 24, 2024.

ADDRESSES: You may send comments identified by docket number using any 
of the following methods:
     Federal eRulemaking Portal: Go to www.regulations.gov and 
follow the online instructions for sending your comments 
electronically.
     Mail: Send comments to Docket Operations, M-30; U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: In accordance with 5 U.S.C. 553(c), DOT solicits comments 
from the public to better inform its rulemaking process. DOT posts 
these comments, without edit, including any personal information the 
commenter provides, to www.regulations.gov, as described in the system 
of records notice (DOT/ALL-14 FDMS), which can be reviewed at 
www.dot.gov/privacy.
    Docket: Background documents or comments received may be read at 
www.regulations.gov at any time. Follow the online instructions for 
accessing the docket or visit Docket Operations in Room W12-140 of the 
West Building Ground Floor at 1200 New Jersey Avenue SE, Washington, 
DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning 
this action, contact Ralph Iovinelli, Office of Environment and Energy 
(AEE-300), Federal Aviation Administration, 800 Independence Ave SW, 
Washington DC 20591; telephone (202) 267-3566; email 
[email protected].

SUPPLEMENTARY INFORMATION:

Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in 
Title 49 of the United States Code. Subtitle I, Section 106 describes 
the authority of the FAA Administrator.
    The Clean Air Act Amendments of 1970, title 42 of the United States 
Code, Chapter 85, Subchapter II, part B, Section 7572, grant the 
Secretary of Transportation the authority to ensure compliance with 
aviation emission standards adopted by the United States EPA. Further, 
49 CFR 1.83(c) delegates to the FAA Administrator the authority to 
``[C]arry out the functions vested in the Secretary by part B of title 
II of the Clean Air Act.''
    This rulemaking adopts regulations to enforce the standards adopted 
by the EPA under its authority in the Clean Air Act (the Act) in 40 CFR 
part 1031 at the time of aircraft certification to control certain 
emissions from airplane engines. This rulemaking is issued under 42 
U.S.C. 7572 and 49 CFR 1.83(c).

Good Cause Statement

    Section 553 of the Administrative Procedure Act (APA) (5 U.S.C. 
553) requires Federal agencies to publish a notice of proposed 
rulemaking unless ``. . . the agency for good cause finds (and 
incorporates the finding in a brief statement of reasons therefor in 
the rules issued) that notice and public procedure thereon are 
impractical, unnecessary, or contrary to the public interest.'' Under 
this section, an agency, upon finding good cause, may issue a final 
rule without seeking comment prior to the rulemaking.
    This rule adopts the procedures necessary for the FAA to implement 
the regulatory emissions limits and test requirements (together 
referred to as standards) for nvPM emitted by aircraft engines adopted 
by the EPA under 42 U.S.C. 7571 (sec. 231 of the Act) (87 FR 72312, 
November 23, 2022) that were effective December 31, 2022. These 
standards are set forth in 40 CFR part 1031. The FAA is statutorily 
required (see 42 U.S.C. 7572 (sec. 232 of the Act)) to incorporate the 
EPA's nvPM emissions standards into its regulations (14 CFR part 34) 
and apply the regulatory requirements that will allow applicants to 
demonstrate compliance with the emissions standards at the time of 
engine airworthiness certification. The FAA has no authority to alter 
the standards (emission limits and test requirements) adopted by the 
EPA for engine emissions in 40 CFR part 1031.
    The emission standards adopted by the EPA in 40 CFR part 1031 
represent the results of widely coordinated

[[Page 31079]]

international efforts and public notice and comment rulemaking. The 
FAA, EPA, industry representatives, and foreign certification 
authorities all participated in a multi-year process that resulted in 
the nvPM standards adopted by the International Civil Aviation 
Organization (ICAO), which the EPA thereafter prescribed in 40 CFR part 
1031. Because the FAA has no authority to change any of the standards 
adopted by the EPA, a solicitation of comments will not result in any 
substantive changes to the standards and would unnecessarily delay 
their implementation.
    Accordingly, the FAA finds that notice and comment on the standards 
and procedures adopted in this rulemaking is unnecessary because the 
FAA does not have authority to make changes to the standards or 
procedures adopted by the EPA and the EPA issued its proposed rule for 
notice and sought public comment on these standards and test procedures 
prior to promulgating them on November 23, 2022.
    Therefore, FAA finds that good cause exists under 5 U.S.C. 
553(b)(3)(B) to waive prior notice and the opportunity for comment 
because such procedures are unnecessary.
    Although the FAA has no authority to change any of the emission 
standards or procedures adopted by the EPA in accordance with the Act, 
the FAA is requesting comment from interested parties regarding the 
parts of this rulemaking that adopt the certification regulations in 14 
CFR part 34 and implement them at the time of aircraft engine 
certification. The FAA will review and consider any comments received. 
Notice of any action the FAA takes as a result of a comment will be 
published in the Federal Register.

Comments Invited

    The FAA encourages interested persons to participate in this 
rulemaking by submitting written comments containing relevant 
information, data, or views. The FAA also invites comments relating to 
the economic, environmental, energy, or federalism impacts that might 
result from the adoption of these requirements. While the FAA cannot 
amend the substance of the rule based on comments, it may take them 
under advisement for future actions. The FAA will consider comments 
received on or before the closing date for comments. The FAA will also 
consider late filed comments to the extent practicable.
    See section VII., ``How to Obtain Additional Information,'' for 
information on how to comment on this final rule and how the FAA will 
handle comments received. That section also contains related 
information about the docket, privacy, and the handling of proprietary 
or confidential business information. In addition, there is information 
on obtaining copies of related rulemaking documents.

I. Executive Summary

    This rulemaking adopts the regulations necessary for the Federal 
Aviation Administration (FAA) to implement the Environmental Protection 
Agency's (EPA) new aircraft engine emissions standards and 
certification test procedures for non-volatile particulate matter 
(nvPM) that were effective December 23, 2022.\1\ The nvPM standards 
replace the historical smoke number (SN) requirements for certain 
larger aircraft engines and create new standards to address 
nvPMmass and nvPMnumber.
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    \1\ 87 FR 72312--Control of Air Pollution From Aircraft Engines: 
Emission Standards and Test Procedures.
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    Since the EPA and FAA share the authority for aircraft engine 
emission standards under the Clean Air Act (the Act),\2\ this action 
modifies 14 CFR part 34 (part 34) by adopting maximum nvPM mass 
concentration (nvPMMC) as the standard that addresses 
emissions plume invisibility, limits for nvPMMC, and limits 
for nvPM mass (nvPMmass) and nvPM number 
(nvPMnum), for certain classes of subsonic turbofan engine 
emissions. As part of this action, the FAA is incorporating by 
reference the ICAO test procedures needed to measure nvPM at 
certification and adding the definitions and abbreviations to part 34 
that are used in the nvPM certification standards. The new nvPM 
emissions standards apply to engines having a rated output greater than 
26.7 kilonewtons (kN). The FAA is also amending its regulations to 
reflect the EPA's application of smoke number (SN) standards to all new 
supersonic engines regardless of size, and by adopting the same 
clarifying language promulgated by the EPA for the current fuel venting 
standard.
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    \2\ Clean Air Act mandates under 42 U.S.C. 7571 and 7572--
Establishment and Enforcement of Standards. 42 U.S.C. 7571: 
Establishment of standards (house.gov) and 42 U.S.C. 7572: 
Enforcement of standards (house.gov)
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    The FAA is adopting the same nvPM emissions limits as those 
promulgated by the EPA and ICAO. Engine manufacturers are already 
complying with ICAO nvPM standards; this rule will not cause 
manufacturers to incur additional costs to certificate an engine in the 
United States. Manufacturers would likely incur higher costs if this 
rule is not implemented, since they would be required to seek 
certification with a non-U.S. authority to remain competitive globally. 
More detail on the cost analysis is provided in Section V. A. of this 
document.
    This final rule fulfills FAA's obligation to implement EPA's new 
emissions standards for U.S. civil aircraft and conforms U.S. 
regulations with the standards and recommended practices (SARPs) 
adopted by ICAO.

II. Background

    Aircraft engine exhaust is comprised of gaseous compounds, and of 
particulate matter that contributes to both visible plume exhaust and 
atmospheric particulate matter. Particulate matter emissions include 
both volatile and non-volatile components. Non-volatile particulate 
matter (nvPM) is emitted directly from the engine and is comprised of a 
small amount of carbon particles (or ``soot'') that did not fully 
convert to the gaseous form of carbon dioxide (CO2) during 
the combustion process. Volatile particulate matter (vPM) condenses and 
agglomerates in the aircraft exhaust plume or where the gaseous 
emissions from the plume react with ambient chemicals present in the 
atmosphere. Since vPM are affected by atmospheric conditions and 
undergo rapid changes when emitted, they are difficult to predict or 
measure accurately. This rule does not address vPM, nor are there 
international standards for aircraft engine vPM emissions.
    In 1973, the U.S. first addressed particulate matter emissions by 
adopting the smoke number (SN) standards of part 34 that focused on 
visible aircraft exhaust plumes. The SN standard was established to 
eliminate the visible particulate matter directly emitted by aircraft 
engines, rendering exhaust plumes invisible to the human eye. SN is 
determined by measuring the opacity of a filter after soot has been 
collected on it during the engine emissions certification test required 
by Sec.  34.23(a).
    In 2013, ICAO recognized that measuring nvPM emissions allowed a 
more comprehensive approach to controlling visible aircraft exhaust 
plumes by describing the nvPM emissions that are most likely to impact 
human health and welfare, and by establishing regulatory limits for 
them. As a result, the ICAO Committee on Aviation Environmental 
Protection (CAEP) began the first of two standard-setting actions work 
programs in its tenth triennial cycle (CAEP/10, 2013-2016) to 
incorporate non-volatile particulate matter emissions measurement and 
limits in ICAO's

[[Page 31080]]

SARPs for turbofan engines greater than 26.7 kilonewtons (kN) of rated 
thrust.
    As part of its first standard setting action, ICAO recognized that 
the measurement known as maximum nvPM mass concentration 
(nvPMMC) is a more accurate and modern replacement for the 
optical visibility standard represented by the long-standing SN 
standard. The visibility limit for nvPMMC was developed by 
ICAO using both measured SN and nvPMMC data from several 
modern engines to derive a SN-to-nvPMMC correlation. This 
correlation was then used to transfer the existing regulatory SN limit 
into an equivalent nvPMMC limit without increasing 
stringency. The nvPMMC measurement standard maintains the 
standard of invisibility of the exhaust plume that was achieved using 
SN but uses modern testing methodologies. The ICAO/CAEP analysis 
confirmed that an nvPMMC standard at maximum concentration 
is equivalent to the existing SN standard in controlling exhaust plume 
visibility.
    In 2017, ICAO adopted the nvPMMC standard for engines 
with a rated output of greater than 26.7 kN to provide for a more 
precise measurement of particulate matter exhaust emissions than was 
possible using the SN standard. The ICAO SARP that included the 
nvPMMC standard was effective January 1, 2020, officially 
replacing ICAO's SN standard for civil subsonic aircraft engines that 
produce more than 26.7 kN of rated thrust.
    From 2016 to 2019 (the CAEP/11 triennial cycle), ICAO set standards 
for two additional parameters for nvPM emissions from affected aircraft 
engines: nvPM mass (nvPMmass) and nvPM number 
(nvPMnum) as the second of the two standard-setting actions. 
These nvPM standards were directed at controlling emissions from larger 
aircraft engines by addressing nvPM levels that are produced near 
airports, measuring nvPM \3\ during landing and takeoff (LTO) cycles. 
The ICAO SARP that included the nvPMmass and 
nvPMnum standards was effective January 1, 2023, for the 
same engines to which the nvPM mass concentration SARP applied.
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    \3\ ICAO SARPs address only aircraft engines large enough to be 
used on international flights, ICAO leaves the regulation of smaller 
engines likely to be operated only domestically to the member 
States.
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    As a signatory State to the Chicago Convention, the United States 
must establish standards that have the highest practicable degree of 
uniformity to the ICAO SARPs, or file a difference. By implementing the 
standards promulgated by EPA \4\ that included ICAO's nvPM emissions 
standards, this rulemaking is the final action the United States needs 
to take to conform U.S. nvPM certification standards to the ICAO SARPs. 
This rule incorporates into 14 CFR part 34 the aircraft engine nvPM 
emissions standards adopted by the EPA in 40 CFR part 1031 that are 
required when certificating certain aircraft engines in the United 
States.
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    \4\ The EPA final rule that amended 40 CFR part 1031 was 
published at 87 FR 72312 (November 22, 2022).
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III. Summary of Regulatory Changes

    This final rule adopts the emissions levels and test requirements 
that will allow the FAA to certificate aircraft engines to the nvPM 
emissions standards developed by ICAO and made effective in the United 
States by the EPA on December 23, 2022. These new nvPM standards apply 
to subsonic aircraft turbofan engines having a rated output greater 
than 26.7 kN.\5\ As a practical matter, the new nvPM emission standards 
allow engine manufacturers to use the same probe and rake collection 
system used to measure gaseous pollutants to simultaneously measure 
nvPM emissions for certification purposes. This simultaneous 
measurement eliminates the separate SN collection and measurement of 
soot on filter paper, reducing the amount of fuel needed to conduct 
separate engine tests, and making the component emissions measurements 
more representative of an engine's output.
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    \5\ In 2003, ICAO found that ``[T]here was an insignificant 
impact on the environment from aircraft engines of less than 26.7 kN 
(6000lb) thrust, and the cost of emissions reduction for these 
engines was high. There was no evidence to support emissions 
regulation for these small engines.'' The 26.7kN applicability for 
emissions has been the accepted standard in FAA part 34 regulations 
such as Sec. Sec.  34.21(d)(1) and 34.23(a)(1).) ICAO has left 
emissions regulation of engines with lesser output to the discretion 
of the member States.
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    The new nvPM emissions standard has three parameters: maximum 
nvPMMC, nvPMmass, and nvPMnum. Maximum 
nvPMMC ensures the measurement continuity for visible 
particle emissions that SN established. nvPMmass, measures 
the total weight (mass) of the non-volatile carbon particles emitted 
during a time-weighted landing and takeoff (LTO) test cycle. 
nvPMnum is a measurement of the number of non-volatile 
carbon particles emitted during the same time-weighted LTO test cycle. 
The addition of nvPMmass and nvPMnum represents 
the first time the component characteristics of non-volatile emissions 
are being measured. The ability to identify and measure these 
components will allow regulatory authorities to establish more 
stringent limits in the future as a means to better protect human 
health and welfare. For a comprehensive discussion of the health 
effects of particulate matter on humans, see the preamble to EPA's 
final rule for nvPM at 87 FR 72319 (Nov 23, 2022).
    The nvPM test and measurement procedures require the use of 
additional equipment and procedures compatible with those currently in 
use for measuring gaseous pollutants. The FAA is both incorporating by 
reference the nvPM test and measurement procedures described in ICAO 
Annex 16, Volume II (as adopted by the EPA), and adding additional test 
procedures in new Sec. Sec.  34.71 and 34.73 in order to fully 
implement the EPA's standards.
    In addition to the nvPM standards and methods described, the FAA 
has included other minor, nonsubstantive changes to the existing 
emissions regulations as they relate to nvPM to make part 34 consistent 
with the EPA regulations of 40 CFR part 1031, as described in Section H 
below. The FAA has also created a centralized incorporation by 
reference (IBR) section to index the ICAO materials that part 34 
incorporates by reference, as described in Section G, below.

IV. Discussion of This Final Rule

    This final rule establishes the certification standards for 
nvPMMC, nvPMmass, and nvPMnum 
emissions from certain classes of subsonic engines that have a rated 
output greater than 26.7 kN, and adopts the associated test procedures 
established by ICAO and adopted by the EPA at 87 FR 72319 (Nov 23, 
2022) required for certification in the United States. These 
regulations replace SN with nvPM as the required emission standard for 
particulate matter for applicable engines, as adopted by the EPA. None 
of the changes made in this rule adding nvPM measurements as a 
requirement for certain engines are meant to affect the SN requirements 
for engines of any class having a rated output of 26.7 kN or less, for 
turboprop engines (Class TP), or for supersonic engines (Class TSS). 
The nvPM requirement is adopted in Sec.  34.25, and the test 
requirements in a new Subpart H to part 34 comprised of Sec. Sec.  
34.71 and 34.73. This rulemaking adds nvPM characteristics to the 
requirements for a finding of similarity of a derivative engine in 
Sec.  34.48. These substantive changes are described as follows.

[[Page 31081]]

A. Addition of Maximum nvPM Mass Concentration Standards for Aircraft 
Engines--Sec. Sec.  34.25(a)(1) and 34.25(c)(1)

    For Class TF, T3, or T8 engines (regulated classes of large 
turbofan engines) with a rated output greater than 26.7 kN, this rule 
replaces the SN requirement with a measurement of a maximum nvPM mass 
concentration (nvPMMC) limit in micrograms per cubic meter 
[[mu]g/m\3\]. This action maintains the standard that aircraft engine 
exhaust plumes remain invisible, which was the intent of the ICAO 
standards adopted in the United States by the EPA. When determining 
nvPMMC, values must be obtained from measurements made 
across the entire thrust range of an engine. The characteristic level 
of the measured maximum nvPMMC value may not exceed the 
regulatory limit established using the formula in Sec.  34.25. The 
required test procedures and compliance demonstration for nvPM are 
discussed in section I.

B. Addition of nvPM Mass and nvPM Number Standards for Aircraft 
Engines--Sec. Sec.  34.25(a)(2) and 34.25(c)(2)

    The standards for nvPMmass and nvPMnum apply 
to all subsonic turbofan and turbojet engines that have a rated output 
greater than 26.7 kN. The nvPMmass limit is the mass of 
emissions of nvPM expressed in milligrams (mg) divided by kN of rated 
thrust, as determined over the LTO cycle. The nvPMnum limit 
is the number of particles divided by kN of rated thrust, as determined 
over the LTO cycle.
    An engine for which an application for an original type certificate 
is submitted on or after January 1, 2023, is subject to the 
nvPMmass and nvPMnum emission limits of Sec.  
34.25. An engine that was type certificated before January 1, 2023, for 
which an application for type design modification is submitted on or 
after January 1, 2023, is also subject to the nvPMmass and 
nvPMnum emission limits of Sec.  34.25. This date is 
consistent with the effective date of the EPA final rule that adopted 
these standards.
    The FAA is incorporating by reference into part 34 the nvPM test 
and measurement procedures of ICAO Annex 16, Volume II, Appendices 4, 6 
and 7. The EPA incorporated these appendices and Appendix 8, which is 
not relevant to FAA regulations,\6\ This incorporation by reference 
continues the FAA use of these procedures in part 34 to conform to 
accepted international standards. These requirements are discussed in 
Section I of this document.
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    \6\ Control of Air Pollution From Aircraft Engines: Emission 
Standards and Test Procedures quotes ``The EPA is incorporating by 
reference Appendix 8 of Annex 16, Volume II, which outlines 
procedures used to estimate measurement system losses, which are a 
required element of the reporting provisions.'' page 72333 in FR Vol 
87 No 225, November 23, 2022.
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C. Smoke Number Standards in Sec.  34.21(e)

    As stated in Section IV, the nvPM standards for engines with a 
rated output greater than 26.7 kN are a replacement for SN requirements 
in certain classes of engines. For all other classes of engines, this 
rule revises Sec.  34.21(e) to group the continuing SN requirements in 
one paragraph for ease of reference; the SN standards had been 
scattered in various sections of part 34 as compliance dates were added 
over time. Consistent with the standards adopted by the EPA and ICAO, 
the SN requirements are unchanged for engines not subject to nvPM. The 
applicability of Sec.  34.21(e) was modified as described here to 
maintain regulatory consistency.
    Section 34.21(e)(1)(A) and (B) carry forward the SN requirements 
for engines of the applicable class and size produced before January 1, 
2023. The SN requirements of paragraph(e)(1)(B) were misplaced in Sec.  
34.23(a)(1) and referenced as a gaseous emission standard. The 
requirement was moved to (e)(1)(B) and Sec.  34.23(a)(1) is marked 
reserved to maintain the integrity of references to the gaseous 
emissions standards of Sec.  34.23.
    Paragraph (e)(1)(C) applies to described engines manufactured after 
January 1, 2023, and contains a modification to the applicability of 
the SN requirements to maintain consistency with EPA regulations. Over 
time, regulatory changes by the U.S. and ICAO resulted in a discrepancy 
of applicability between the two sets of regulations. If the United 
States maintained its applicability division, an engine with exactly 
26.7 kN of rated output would be subject to the SN standard in other 
ICAO member States, but subject to nvPM standards in the United States. 
In its rulemaking, the EPA adopted the ICAO standard for the division 
between SN and nvPM applicability. The FAA is adopting the same EPA and 
ICAO applicability descriptors to prevent a situation where an engine 
of exactly 26.7 kN of rated output would, without reason, be subject to 
two different standards. Accordingly, the SN standard for engines 
manufactured on or after January 1, 2023, has been modified to apply to 
engines having a rated output of 26.7 kN or less. The FAA is not aware 
of any engines rated at exactly 26.7 kN, so there are no practical 
consequences to this realignment, and it has no retroactive 
applicability.
    Section 34.21(e)(2) contains the SN requirements for certain 
classes of engines manufactured on or after January 1, 1984, and before 
January 1, 2023. Engines of those classes manufactured on or after 
January 1, 2023, are subject to the new nvPM requirements of Sec.  
34.25.
    Section 34.21(e)(3) carries forward the SN standard for certain 
turboprop (class TP) engines manufactured on or after January 1, 1984. 
This requirement is unchanged.
    Section 34.21(e)(4) makes the SN standard appliable to all 
supersonic (class TSS) engines regardless of rated thrust. Because 
emissions standards for supersonic engines have not yet been agreed to 
internationally, these engines were not included by ICAO in the new 
nvPM standard. The EPA adopted the ICAO standard for SN to apply to all 
supersonic engines regardless of rated output in 40 CFR part 1031. This 
regulation carries forward that requirement in part 34.

D. Fuel Venting Description Sec.  34.11

    The fuel venting standard in part 34 subpart B prohibits the 
discharge of fuel to the atmosphere following engine shutdown. Fuel 
venting emissions are described as fuel discharge during all normal 
ground and flight operations. Following discussions with the EPA and 
ICAO, this rule adds the word ``liquid'' before ``fuel'' in the fuel 
venting requirements to prevent the application of the regulation to 
small amounts of fuel that vaporize on hot engine parts after shutdown. 
Small amounts of vaporizing fuel was not the concern of the fuel 
venting prohibition drafted in the 1960s, which was intended to address 
the then-common practice of dumping large amounts of liquid fuel on the 
ground after engine shutdown. This change will not have any effect on 
the requirements for engine type certification, and is a concept 
commonly understood in the industry.

E. Adding nvPM Characteristics for Derivative Engine Findings--Sec.  
34.48

    Section 34.48 prescribes standards for finding that an engine is a 
``derivative engine for emissions purposes'' by assessing the emissions 
similarity between an engine and its proposed derivative. Status as a 
derivative engine determines whether the proposed derivative must 
undergo complete emissions testing. The addition of an nvPM standard 
requires that the derivative engine considerations also include nvPM 
characteristics for engines that may be considered as a

[[Page 31082]]

derivative of an engine manufactured after January 1, 2023. These 
emission similarity ranges for nvPM have been included in Sec.  
34.48(b)(1)(v). Section 34.48(b)(3) is added for consistency with EPA 
regulations. The requirements for nvPM testing of a derivative engine 
are addressed in Sec.  34.25(b).

F. Addition of Test Procedures and Compliance Demonstration for nvPM--
Subpart H, Sec. Sec.  34.71 and 34.73

    In order to implement the nvPM standards adopted by the EPA, FAA 
regulations must include effective test and measurement procedures in 
the emissions certification requirements for use by manufacturers. 
These tests and procedures have been placed in a new subpart H to part 
34 as Sec. Sec.  34.71 and 34.73.
    Section 34.71 identifies the nvPM emissions test requirements, such 
as the minimum number of emissions test runs required, the number of 
engines of the same type design that may be used to gather test data, 
and the operational conditions required for emissions certification 
(Sec.  34.71 (b), (c), and (g)). The section also includes test fuel 
specifications (Sec.  37.71 (d)), a description of the LTO cycle (Sec.  
34.71(h)), and how to prepare and operate an engine for emissions 
certification (Sec.  34.71 (f)). Section 34.71(i) states how 
characteristic values, in conjunction with Table A6-1 of Annex 16 Vol 
II, Appendix 6, are to be determined.
    Many of the test and measurement procedures required for nvPM were 
identified and described by ICAO. Section 34.71(e)(1) includes an 
incorporation by reference of ICAO Annex 16, Volume II and its 
Appendices requiring that those tests and procedures in the applicable 
Annex appendices be used when measuring and collecting data, including 
the other requirements of Sec.  34.71.
    Section 34.71 (e)(2) instructs the applicant on the procedures 
necessary when requesting a deviation from any of the test procedures 
or compliance demonstrations of subpart H. The FAA expects that any 
such deviation request would be from a test or procedure that was 
included in the approved test plan, but was discovered to be unworkable 
before the test is actually conducted. Any deviation proposed must be 
approved by the FAA before any emissions test is conducted. The FAA 
will consult with the EPA prior to making a written determination on 
any requested deviation.
    Section 34.71(j) requires that all measurements be included in nvPM 
calculations. This section also cautions that if an applicant seeks to 
exclude any measurements, that data must be submitted to the FAA with 
justification for the exclusion, and that the exclusions must be 
approved by the FAA before the applicant makes any nvPM calculations.
    Section 34.73 requires applicants to perform a compliance 
demonstration that shows the engine emissions of nvPM are within the 
applicable limits provided in Sec.  34.25. A demonstration of 
compliance includes calculations to determine the characteristic nvPM 
emissions levels for maximum nvPMMC, nvPMmass, 
and nvPMnum using the measurements collected in accordance 
with Sec.  34.71. The applicant's compliance demonstration must be 
conducted within 90% confidence intervals (Sec.  34.73(d)), use the 
required rounding in calculations (Sec.  34.73(a)(3)), and correct for 
standard temperature and pressure as prescribed in the ICAO Annex 16, 
Volume II Appendix 1.
    Section 34.73(c)(1) directs the applicant to conduct the minimum 
number of measurements at the thrust settings given in Sec.  34.71(h). 
However, this section also provides an applicant with the flexibility 
to make as many additional measurements as it chooses across the entire 
thrust range of an engine when measuring nvPM. More measurements 
conducted across the thrust range of an engine result in improved 
understanding of any trending nvPM behavior. Section 34.71(c)(1) also 
allows an applicant to choose one of the three equivalent evaluation 
methods listed in that section when calculating nvPMMC. Once 
nvPM emissions certification testing is complete, Sec.  34.73(e) 
identifies the required information to be reported to the FAA in the 
emissions test report. The FAA notes that the EPA has separate 
reporting requirements that are not part of this rulemaking.

G. Incorporation by Reference (IBR) Section

    This final rule includes a new section, Sec.  34.4, that indexes 
all material incorporated by reference in part 34. The FAA determined 
that it was appropriate with this final rule to create a centralized 
IBR section indexing all the materials incorporated by reference in 
Part 34, for ease of reference and future revision.
    The OFR has regulations concerning incorporation by reference (1 
CFR part 51). These regulations require that, for a final rule, 
agencies must discuss in the preamble the way in which the materials 
that the agency incorporated by reference are reasonably available to 
interested persons, and how interested parties can obtain the 
materials. In addition, in accordance with 1 CFR 51.5(b), the agency 
must summarize the material in the preamble of the final rule.
    Because this rule was passed to harmonize United States regulations 
with international standards, this final rule incorporates Annex 16 to 
the Convention on International Civil Aviation: Environmental 
Protection, Volume II--Aircraft Engine Emissions, Fourth Edition, July 
2017 (ICAO Annex 16, Volume II). Appendices 1,4, 6, and of the 2017 
Annex are referenced in Sec.  34.71 and 34.73, and appendices 4 and 6 
of the Annex are referenced in Sec.  34.73. The content of these 
appendices is described above, in sub-part F.
    The 2008, Third Edition, of the Annex is referenced in Sec. Sec.  
34.1 and 34.60. The incorporation by reference of the 2008, Third 
Edition, of the Annex was approved by the Director of the Federal 
Register as of December 31, 2012 (77 FR 76842). The new Sec.  34.4 
includes the 2008 and 2017 editions of the ICAO Annex as well. All 
approved material is available for inspection at the FAA. Contact the 
FAA Office of Rulemaking (ARM), 800 Independence Avenue SW, Washington, 
DC 20590 (telephone 202-267-9677). Interested parties can also purchase 
the Annex online from ICAO at: store.icao.int/en/annexes/annex-16.

H. Miscellaneous Amendments

    This rule includes the following changes to part 34 to improve the 
clarity of the nonvolatile particulate matter emissions standards, 
align the provisions described with those of the EPA in 40 CFR part 
1031 (formerly 40 CFR part 87), and make other minor changes as 
described:
    (1) Definitions in Sec.  34.1. This rule adds a definition of nvPM, 
and revises the definition of ``Derivative engine for emissions 
certification purposes'' for consistency with EPA regulations in 40 CFR 
part 1031 and ICAO Annex 16 Volume II. This rule revises the definition 
of ``Reference day condition'' to include a more accurate value for 
specific humidity that is recognized in the general scientific 
community and is consistent with the definitions used by the EPA and 
ICAO. This rule removes the definition of ``Fuel venting'' from Sec.  
34.1 in favor of the more specific description of fuel venting in Sec.  
34.11, where it applies.
    (2) Abbreviations in Sec.  34.2: The following terms are added to 
the list of abbreviations in Sec.  34.2: nvPM, nvPMMC, 
nvPMmass, and nvPMnum. The abbreviation ``lb'' is 
corrected to ``lbf.'' Pound force (lbf) is used in part 34 as the 
English measurement equivalent of a rated output stated in kilonewton

[[Page 31083]]

(kN). The abbreviation ``lb'' refers to pounds mass. Three 
abbreviations used in part 34 were found to be missing from the Sec.  
34.2 list and are added in this rule: m for meter, mg for milligram(s), 
and [micro]g for microgram(s). The amendment includes the full 
corrected list of abbreviations used in part 34.
    (3) Updated references to EPA regulations: The replacement of 
references to 40 CFR part 87 with updated references to 40 CFR part 
1031 in Sec. Sec.  34.3, 34.6(h) and 34.7(d). In the case of Sec.  
34.3, the references were numerous, and some were more specific, such 
that the FAA chose to set out the text of the entire section, rather 
than describe individual instances.
    (4) Updated references to 14 CFR part 34: The removal of the 
acronym ``FAR,'' replacing it with an appropriate reference to the 
regulations of part 34 or 40 CFR part 1031. The term ``FAR'' is not a 
recognized legal reference to the regulations in Title 14 of the Code 
of Federal Regulations.

V. Regulatory Notices and Analyses

    Federal agencies consider impacts of regulatory actions under a 
variety of executive orders and other requirements. First, Executive 
Order 12866 and Executive Order 13563, as amended by Executive Order 
14094 (``Modernizing Regulatory Review''), direct that each Federal 
agency shall propose or adopt a regulation only upon a reasoned 
determination that the benefits of the intended regulation justify the 
costs. Second, the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) 
requires agencies to analyze the economic impact of regulatory changes 
on small entities. Third, the Trade Agreements Act (Pub. L. 96-39) 
prohibits agencies from setting standards that create unnecessary 
obstacles to the foreign commerce of the United States. Fourth, the 
Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires agencies 
to prepare a written assessment of the costs, benefits, and other 
effects of proposed or final rules that include a Federal mandate that 
may result in the expenditure by State, local, and tribal governments, 
in the aggregate, or by the private sector, of $100 million or more 
(adjusted annually for inflation) in any one year. The current 
threshold after adjustment for inflation is $177 million using the most 
current (2022) Implicit Price Deflator for the Gross Domestic Product. 
This portion of the preamble presents the FAA's analysis of the 
economic impacts of this rule.
    In conducting these analyses, the FAA has determined that this 
rule: will result in benefits that justify costs; is not an 
economically ``significant regulatory action'' as defined in section 
3(f) of Executive Order 12866; will not have a significant economic 
impact on a substantial number of small entities; will not create 
unnecessary obstacles to the foreign commerce of the United States; and 
will not impose an unfunded mandate on State, local, or tribal 
governments, or on the private sector.

A. Regulatory Impact Analysis

    The FAA expects minimal cost savings to result from the final rule. 
The FAA will be implementing emission standards promulgated by the EPA 
on November 23, 2022, which adopted the standards previously set by 
ICAO. The EPA standards conform to the ICAO standards and the FAA does 
not have the authority to change the emissions standards adopted by the 
EPA. Manufactures are already complying with the ICAO nvPM standards to 
be able to market their aircraft worldwide, so this final rule will not 
place any new costs on manufacturers when engines are certificated in 
the United States.
    Manufacturers would likely incur some extra costs if this rule is 
not implemented, as they would be required to seek certification with a 
non-U.S. certification authority. The FAA identified five U.S.-based 
manufacturers that are affected by this final rule. The costs of full 
emissions certification that includes nvPM emissions in the U.S. is 
estimated to average $548,733 \7\ per engine tested, in 2019 
dollars.\8\ However, the flat fee for certification in the European 
Union is 405,310 euros \9\ or $453,875 in 2019 currency exchange rate 
terms.\10\ These certification cost estimates do not account for the 
transportation, staffing, and administrative costs manufacturers would 
have to incur.\11\
---------------------------------------------------------------------------

    \7\ The $500,000 cost estimate provided to ICAO is in 2013 
dollars which calculates to $548,733 in 2019 dollars. The Bureau of 
Economic Analysis Gross Domestic Price Deflator data was used to 
convert the cost estimate into 2019 dollars. https://apps.bea.gov/iTable/?reqid=19&step=3&isuri=1&1921=survey&1903=11#eyJhcHBpZCI6MTksInN0ZXBzIjpbMSwyLDMsM10sImRhdGEiOltbIk5JUEFfVGFibGVfTGlzdCIsIjExIl0sWyJDYXRlZ29yaWVzIiwiU3VydmV5Il0sWyJGaXJzdF9ZZWFyIiwiMjAxMCJdLFsiTGFzdF9ZZWFyIiwiMjAyMiJdLFsiU2NhbGUiLCIwIl0sWyJTZXJpZXMiLCJBIl1dfQ=.
    \8\ Industry average cost estimates for engine emissions 
certification provided to ICAO as part of the nvPM emissions 
standard updates to Annex 16, Volume II.
    \9\ https://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1591083932919&uri=CELEX:32019R2153.
    \10\ The 2019 annual average exchange rate of 1.1198 was used to 
calculate the value in dollar terms. 1/0.893 = 1.1198. https://www.irs.gov/individuals/international-taxpayers/yearly-average-currency-exchange-rates.
    \11\ Manufacturers may shop for the best price with other non-
U.S. authorities, however, we expect costs savings to be minimal in 
all situations due to the flat fees, costs of transportation, 
staffing, and administrative costs associated with the 
certification.
---------------------------------------------------------------------------

B. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) of 1980, (5 U.S.C. 601-612), 
as amended by the Small Business Regulatory Enforcement Fairness Act of 
1996 (Pub. L. 104-121) and the Small Business Jobs Act of 2010 (Pub. L. 
111-240), requires Federal agencies to consider the effects of the 
regulatory action on small business and other small entities and to 
minimize any significant economic impact. The term ``small entities'' 
comprises small businesses and not-for-profit organizations that are 
independently owned and operated and are not dominant in their fields, 
and governmental jurisdictions with populations of less than 50,000.
    As described in the RIA, the FAA identified five U.S. manufacturers 
that would be affected by this final rule. Based on the Small Business 
Administration (SBA) size standard for aircraft engine and engine parts 
manufacturing (Table 1), all five manufacturers are large businesses. 
If an agency determines that a rulemaking will not result in a 
significant economic impact on a substantial number of small entities, 
the head of the agency may so certify under section 605(b) of the RFA. 
Therefore, as provided in section 605(b) and based on the foregoing, 
the head of FAA certifies that this rulemaking will not result in a 
significant economic impact on a substantial number of small entities. 
The FAA welcomes comments on the basis for this certification.

[[Page 31084]]



                              Table 1--Small Business Administration Size Standard
----------------------------------------------------------------------------------------------------------------
               NAICS code                            Description                        Size standard
----------------------------------------------------------------------------------------------------------------
336412..................................  Aircraft Engine and Engine Parts  1,500 Employees.
                                           Manufacturing.
----------------------------------------------------------------------------------------------------------------
Source: SBA (2022).\12\
NAICS--North American Industrial Classification System.

C. International Trade Impact Assessment
---------------------------------------------------------------------------

    \12\ Small Business Administration (SBA). 2022. Table of Size 
Standards. Effective October 1, 2022. https://www.sba.gov/document/support-table-size-standards.
---------------------------------------------------------------------------

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the 
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal 
agencies from establishing standards or engaging in related activities 
that create unnecessary obstacles to the foreign commerce of the United 
States. Pursuant to these Acts, the establishment of standards is not 
considered an unnecessary obstacle to the foreign commerce of the 
United States, so long as the standard has a legitimate domestic 
objective, such as the protection of safety and does not operate in a 
manner that excludes imports that meet this objective. The statute also 
requires consideration of international standards and, where 
appropriate, that they be the basis for U.S. standards.
    The FAA has assessed the potential effect of this rule and 
determined that it maintains the same standards for engine emissions 
certification of nvPM as was adopted by ICAO. As a result, the FAA does 
not consider this rule as creating an unnecessary obstacle to foreign 
commerce.

D. Unfunded Mandates Assessment

    The Unfunded Mandates Reform Act of 1995 (2 U.S.C. 1531-1538) 
governs the issuance of Federal regulations that require unfunded 
mandates. An unfunded mandate is a regulation that requires a State, 
local, or tribal government or the private sector to incur direct costs 
without the Federal government having first provided the funds to pay 
those costs. The FAA determined that this final rule will not result in 
the expenditure of $177 million or more by State, local, or tribal 
governments, in the aggregate, or the private sector, in any one year.

E. Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires 
that the FAA consider the impact of paperwork and other information 
collection burdens imposed on the public. The FAA has determined that 
there is no new requirement for information collection associated with 
this final rule since emissions testing is already required as part of 
aircraft engine certification.

F. International Compatibility and Cooperation

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to conform to 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA has 
reviewed the corresponding ICAO Standards and Recommended Practices and 
has identified the no differences with these regulations. This 
regulation is a conforming action to adopt the same standards for nvPM 
certification that are contained in the ICAO SARPs.

G. Environmental Analysis

    FAA Order 1050.1F identifies FAA actions that are categorically 
excluded from preparation of an environmental assessment or 
environmental impact statement under the National Environmental Policy 
Act (NEPA) in the absence of extraordinary circumstances. The FAA has 
determined this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 5-6.6f for regulations and involves 
no extraordinary circumstances.

H. Regulations Affecting Intrastate Aviation in Alaska

    Section 1205 of the FAA Reauthorization Act of 1996 (110 Stat. 
3213) requires the Administrator, when modifying 14 CFR regulations in 
a manner affecting intrastate aviation in Alaska, to consider the 
extent to which Alaska is not served by transportation modes other than 
aviation, and to establish appropriate regulatory distinctions. Because 
this final rule sets standards for aircraft engine emissions at the 
time of certification, no effect on intrastate aviation in Alaska is 
expected.

VI. Executive Order Determinations

A. Executive Order 13132, Federalism

    The FAA has analyzed this final rule under the principles and 
criteria of Executive Order (E.O.) 13132, Federalism. The FAA has 
determined that this action will not have a substantial direct effect 
on the States, or the relationship between the Federal Government and 
the States, or on the distribution of power and responsibilities among 
the various levels of government, and, therefore, will not have 
federalism implications.

B. Executive Order 13175, Consultation and Coordination With Indian 
Tribal Governments

    Consistent with Executive Order 13175, Consultation and 
Coordination with Indian Tribal Governments,\13\ and FAA Order 1210.20, 
American Indian and Alaska Native Tribal Consultation Policy and 
Procedures,\14\ the FAA ensures that Federally Recognized Tribes 
(Tribes) are given the opportunity to provide meaningful and timely 
input regarding proposed Federal actions that have the potential to 
have substantial direct effects on one or more Indian tribes, on the 
relationship between the Federal government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes; or to affect uniquely or significantly 
their respective Tribes. The FAA has not identified any unique or 
significant effects, environmental or otherwise, on tribes resulting 
from this final rule.
---------------------------------------------------------------------------

    \13\ 65 FR 67249 (Nov. 6, 2000).
    \14\ FAA Order No. 1210.20 (Jan. 28, 2004), available at http://www.faa.gov/documentLibrary/media/1210.pdf.
---------------------------------------------------------------------------

C. Executive Order 13211, Regulations That Significantly Affect Energy 
Supply, Distribution, or Use

    The FAA analyzed this final rule under E.O. 13211, Actions 
Concerning Regulations that Significantly Affect Energy Supply, 
Distribution, or Use (May 18, 2001). The FAA has determined that this 
rule is not a ``significant energy action'' under the executive order 
and is not likely to have a significant adverse effect on the supply, 
distribution, or use of energy.

D. Executive Order 13609, Promoting International Regulatory 
Cooperation

    Executive Order 13609, Promoting International Regulatory 
Cooperation, promotes international regulatory cooperation to meet 
shared challenges

[[Page 31085]]

involving health, safety, labor, security, environmental, and other 
issues and reduce, eliminate, or prevent unnecessary differences in 
regulatory requirements. The FAA has analyzed this action under the 
policy and agency responsibilities of Executive Order 13609. The FAA 
has determined that this action will eliminate differences between U.S. 
aviation standards and those of other civil aviation authorities by 
implementing the same aircraft certification requirements for nvPM 
emissions that are in ICAO Annex 16.

VII. How To Obtain Additional Information

A. Electronic Access and Filing

    A copy of this final rule, any background material, and all 
comments received may be viewed online at www.regulations.gov using the 
docket number listed above. Electronic retrieval help and guidelines 
are available on the website. It is available 24 hours each day, 365 
days each year. An electronic copy of this document may also be 
downloaded from the Office of the Federal Register's website at 
www.federalregister.gov and the Government Publishing Office's website 
at www.govinfo.gov. A copy may also be found at the FAA's Regulations 
and Policies website at www.faa.gov/regulations_policies.
    Copies may also be obtained by sending a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW, Washington, DC 20591, or by calling (202) 267-9677. 
Commenters must identify the docket or notice number of this 
rulemaking.
    All documents the FAA considered in developing this final rule, 
including economic analyses and technical reports, may be accessed in 
the electronic docket for this rulemaking.

B. Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 
1996 requires the FAA to comply with small entity requests for 
information or advice about compliance with statutes and regulations 
within its jurisdiction. A small entity with questions regarding this 
document may contact its local FAA official, or the person listed under 
the FOR FURTHER INFORMATION CONTACT heading at the beginning of the 
preamble. To find out more about SBREFA on the internet, visit 
www.faa.gov/regulations_policies/rulemaking/sbre_act/.

List of Subjects in 14 CFR Part 34

    Aircraft, Aviation safety, Air pollution control, Incorporation by 
reference, Reporting and recordkeeping requirements.

    In consideration of the foregoing, the Federal Aviation 
Administration is amending chapter I of title 14, Code of Federal 
Regulations as follows:

PART 34--FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE 
ENGINE POWERED AIRPLANES

0
1. The authority citation for part 34 continues to read as follows:

    Authority:  42 U.S.C. 4321 et seq., 7572; 49 U.S.C. 106(g), 
40113, 44701-44702, 44704, 44714.

Subpart A--General Provisions

0
2. Amend Sec.  34.1 by:
0
a. Revising and republishing the definition for Characteristic level;
0
b. Revising the definition for Derivative engines for emissions 
certification purposes;
0
c. Removing the definition for Fuel venting emissions;
0
d. Adding in alphabetical order a definition for Non-volatile 
particulate matter; and
0
e. Revising the definition for Reference day conditions.
    The revisions, republication, and addition read as follows:


Sec.  34.1  Definitions.

* * * * *
    Characteristic level has the meaning given in Appendix 6 of ICAO 
Annex 16 as of July 2008 (incorporated by reference, see Sec.  34.4). 
The characteristic level is a calculated emission level for each 
pollutant based on a statistical assessment of measured emissions from 
multiple tests.
* * * * *
    Derivative engine for emissions certification purposes means an 
engine that is similar in design to an engine that has demonstrated 
compliance with the applicable exhaust emission standards of this part, 
as determined by the FAA, and has a U.S. type certificate issued in 
accordance with part 33 of this chapter.
* * * * *
    Non-volatile particulate matter (nvPM) means emitted particles that 
remain at the exhaust nozzle exit plane of a gas turbine engine, and 
that did not volatilize after being heated to a temperature of at least 
350 [deg]C.
* * * * *
    Reference day condition means the reference ambient conditions to 
which the measured smoke, nvPM, and gaseous emissions must be 
corrected. The reference day conditions are as follows:

(1) Temperature = 15 [deg]C,
(2) Specific humidity = 0.00634 kg H2O/kg of dry air, and
(3) Pressure = 101.325 kPa
* * * * *

0
3. Revise Sec.  34.2 to read as follows:


Sec.  34.2  Abbreviations.

    The abbreviations used in this part have the following meanings in 
both upper and lower case:

CO2 Carbon dioxide
CO Carbon monoxide
EPA United States Environmental Protection Agency
FAA Federal Aviation Administration, United States Department of 
Transportation
g Gram(s)
HC Hydrocarbon(s)
HP Horsepower
hr Hour(s)
H2O Water
kg Kilogram(s)
kJ Kilojoule(s)
kN Kilonewton(s)
kW Kilowatt(s)
lbf Pound force
LTO Landing and takeoff
m Meter(s)
mg Milligram(s)
[micro]g Microgram(s)
min Minute(s)
MJ Megajoule(s)
NOX Oxides of nitrogen
nvPM Non-volatile particulate matter
nvPMmass Non-volatile particulate matter mass
nvPMMC Non-volatile particulate matter mass concentration
nvPMnum Non-volatile particulate matter number
Pa Pascal(s)
rO Rated output
rPR Rated pressure ratio
sec Second(s)
SP Shaft power
SN Smoke number
T Temperature in degrees Kelvin
TIM Time in mode
[deg]C Degrees Celsius
% Percent

0
4. Revise and republish Sec.  34.3 to read as follows:


Sec.  34.3  General requirements.

    (a) This part provides for the approval or acceptance by the 
Administrator or the Administrator of the EPA of testing and sampling 
methods, analytical techniques, and related equipment not identical to 
those specified in this part. Before either approves or accepts any 
such alternate, equivalent, or otherwise

[[Page 31086]]

nonidentical procedures or equipment, the Administrator or the 
Administrator of the EPA shall consult with the other in determining 
whether or not the action requires rulemaking under sections 231 and 
232 of the Clean Air Act, as amended, consistent with the 
responsibilities of the Administrator of the EPA and the Secretary of 
Transportation under sections 231 and 232 of the Clean Air Act.
    (b) Under section 232 of the Act, the Secretary of Transportation 
issues regulations to ensure compliance with 40 CFR part 1031. This 
authority has been delegated to the Administrator of the FAA in 
accordance with 49 CFR 1.47.
    (c) This part applies to civil airplanes that are powered by 
aircraft gas turbine engines of the classes specified herein and that 
have U.S. standard airworthiness certificates.
    (d) Pursuant to the definition of ``aircraft'' in 40 CFR 1031.205, 
this regulation applies to civil airplanes that are powered by aircraft 
gas turbine engines of the classes specified herein and that have 
foreign airworthiness certificates that are equivalent to U.S. standard 
airworthiness certificates. This regulation applies only to those 
foreign civil airplanes that, if registered in the United States, would 
be required by applicable regulations to have a U.S. standard 
airworthiness certificate in order to conduct the operations intended 
for the airplane. Pursuant to 40 CFR 1031.5, this regulation does not 
apply where it would be inconsistent with an obligation assumed by the 
United States to a foreign country in a treaty, convention, or 
agreement.
    (e) Reference in this regulation to 40 CFR part 1031 refers to 
title 40 of the Code of Federal Regulations, chapter I--Environmental 
Protection Agency, part 1031, Control of Air Pollution from Aircraft 
and Aircraft Engines (40 CFR part 1031).
    (f) This part contains regulations that implement compliance with 
certain standards contained in 40 CFR part 1031. If EPA takes any 
action, including the issuance of an exemption or issuance of a revised 
or alternate procedure, test method, or other regulation, the effect of 
which is to relax or delay the effective date of any provision of 40 
CFR part 1031 that is made applicable to an aircraft under this part, 
the Administrator of FAA will grant a general administrative waiver of 
the more stringent requirements until this part is amended to reflect 
the requirements relaxed by EPA.
    (g) Unless otherwise stated, all terminology and abbreviations in 
this part that are defined in 40 CFR part 1031 have the meaning 
specified in that part, and all terms in 40 CFR part 1031 that are not 
defined in that part but that are used in this part have the meaning 
given them in the Clean Air Act, Public Law 91-604, as amended.
    (h) All interpretations of 40 CFR part 1031 that are promulgated by 
the EPA also apply to this part.
    (i) If the EPA, under 40 CFR part 1031, approves or accepts any 
testing and sampling procedures or methods, analytical techniques, or 
related equipment not identical to those specified in that part, this 
part requires an applicant to show that such alternate, equivalent, or 
otherwise non-identical procedures have been complied with, and that 
such alternate equipment was used to show compliance, unless the 
applicant elects to comply with those procedures, methods, techniques, 
and equipment specified in 40 CFR part 1031.
    (j) If the EPA, under 40 CFR 1031, prescribes special test 
procedures for any aircraft or aircraft engine that is not susceptible 
to satisfactory testing using the procedures in 40 CFR part 1031, the 
applicant must demonstrate to the FAA Administrator that they are in 
compliance with those special test procedures.
    (k) Wherever 40 CFR part 1031 requires agreement, acceptance, or 
approval by the Administrator of the EPA, this part requires a showing 
that such agreement or approval has been obtained.
    (l) Pursuant to 42 U.S.C. 7573, no state or political subdivision 
thereof may adopt or attempt to enforce any standard respecting 
emissions of any air pollutant from any aircraft or engine thereof 
unless that standard is identical to a standard made applicable to the 
aircraft by the terms of this part.
    (m) If EPA, by regulation or exemption, relaxes a provision of 40 
CFR part 1031 that is implemented in this part, no state or political 
subdivision thereof may adopt or attempt to enforce the terms of this 
part that are superseded by the relaxed requirement.
    (n) If any provision of this part is rendered inapplicable to a 
foreign aircraft as provided in 40 CFR 1031.5 (international 
agreements), and paragraph (d) of this section, that provision may not 
be adopted or enforced against that foreign aircraft by a state or 
political subdivision thereof.
    (o) For exhaust emissions requirements of this part that apply 
beginning February 1, 1974, January 1, 1976, January 1, 1978, January 
1, 1984, and August 9, 1985, continued compliance with those 
requirements is shown for engines for which the type design has been 
shown to meet those requirements, if the engine is maintained in 
accordance with applicable maintenance requirements of 14 CFR chapter 
I. All methods of demonstrating compliance and all model designations 
previously found acceptable to the Administrator shall be deemed to 
continue to be an acceptable demonstration of compliance with the 
specific standards for which they were approved.
    (p) Each applicant must allow the Administrator to make, or 
witness, any test necessary to determine compliance with the applicable 
provisions of this part.

0
5. Amend Subpart A by adding Sec.  34.4 to read as follows:


Sec.  34.4  Incorporation by Reference.

    Certain material is incorporated by reference into this part with 
the approval of the Director of the Federal Register under 5 U.S.C. 
552(a) and 1 CFR part 51). All approved material is available for 
inspection at the FAA and at the National Archives and Records 
Administration (NARA). Contact the FAA Office of Rulemaking (ARM), 800 
Independence Avenue SW, Washington, DC 20590 (telephone 202-267-9677) 
For information on the availability of this material at NARA, visit 
www.archives.gov/federal-register/cfr/ibr-locations or email 
[email protected].
    (a) The material may be obtained from the following source: 
International Civil Aviation Organization (ICAO): Document Sales Unit, 
999 University Street, Montreal, Quebec H3C 5H7, Canada, phone + 1 514-
954-8022, or www.icao.int.
    (1) Annex 16 to the Convention on International Civil Aviation: 
Environmental Protection, Volume II--Aircraft Engine Emissions, Third 
Edition, July 2008 (ICAO Annex 16); in Sec. Sec.  34.1 and 34.60.
    (2) Annex 16 to the Convention on International Civil Aviation: 
Environmental Protection, Volume II--Aircraft Engine Emissions, Fourth 
Edition, July 2017 (ICAO Annex 16, Volume II), in Sec. Sec.  34.71 and 
34.73.
    (b) [Reserved]

0
6. Amend Sec.  34.6 by revising paragraph (b) to read as follows:


Sec.  34.6  Aircraft safety.

* * * * *
    (b) Consistent with 40 CFR part 1031, if the FAA Administrator 
determines that any emission control regulation in this part cannot be 
safely applied to an aircraft, that provision may not be adopted or 
enforced against that aircraft

[[Page 31087]]

by any state or political subdivision thereof.
* * * * *

0
7. Amend Sec.  34.7 by revising paragraph (d) to read as follows:


Sec.  34.7   Exemptions.

* * * * *
    (d) Applicants seeking exemption from other emissions standards of 
this part and 40 CFR 1031.15. Applicants must request exemption from 
both the FAA and the EPA, even where the underlying regulatory 
requirements are the same. The FAA and EPA will jointly consider such 
exemption requests, and will assure consistency in the respective 
agency determinations.
* * * * *

0
8. Amend Sec.  34.11 by revising paragraph (a) and the introductory 
text of paragraph (c) to read as follows:


Sec.  34.11  Standard for fuel venting emissions.

    (a) No liquid fuel venting emissions shall be discharged into the 
atmosphere from any new or in-use aircraft gas turbine engine subject 
to the subpart. This paragraph is directed at the elimination of 
intentional discharge to the atmosphere of fuel drained from fuel 
nozzle manifolds after engines are shut down and does not apply to 
normal fuel seepage from shaft seals, joints, and fittings.
* * * * *
    (c) As applied to an airframe or an engine, any manufacturer or 
operator may show compliance with the liquid fuel venting and emissions 
requirements of this section that were effective beginning February 1, 
1974 or January 1, 1975, by any means that prevents the intentional 
discharge of fuel from fuel nozzle manifolds after the engines are shut 
down. Acceptable means of compliance include one of the following:
* * * * *

0
9. Amend Sec.  34.21 by revising paragraph (e) to read as follows:


Sec.  34.21  Standards for exhaust emissions.

* * * * *
    (e) Smoke exhaust emissions from each gas turbine engine shall not 
exceed:
    (1)(A) For Class TF of rated output less than 26.7 kN (6,000 lbf) 
manufactured on or after August 9, 1985, and before July 18, 2012:

SN = 83.6(rO)-0.274 (rO is in kN) not to exceed a maximum of 
SN = 50.

    (B) For Classes TF, T3, and T8 of rated output less than 26.7 kN 
(6,000 lbf) manufactured on or after July 18, 2012, and before January 
1, 2023:

SN = 83.6(rO)-0.274 or 50.0, whichever is smaller.

    (C) For Classes TF, T3, and T8 of rated output of 26.7 kN (6,000 
lbf) or less manufactured on or after January 1, 2023:

SN = 83.6(rO)-0.274 or 50.0, whichever is smaller.

    (2) For Classes T3, T8, TSS, and TF of rated output greater than or 
equal to-26.7 kN (6,000 lbf) manufactured on or after January 1, 1984, 
and before January 1, 2023:

SN = 83.6(rO)-0.274 (rO is in kN) not to exceed a maximum of 
SN = 50.

    (3) For Class TP of rated output equal to or greater than 1,000 kW 
manufactured on or after January 1, 1984:

SN = 187(rO)-0.168 (rO is in kW).

    (4) For Class TSS manufactured on or after January 1, 2023:

SN = 83.6(rO)-0.274 (rO is in kN) not to exceed a maximum of 
SN = 50.
* * * * *


Sec.  34.23  [Amended]

0
10. Amend Sec.  34.23 by removing and reserving paragraph (a)(1).

0
11. Amend Subpart C by adding Sec.  34.25 to read as follows:


Sec.  34.25  Non-volatile particulate emissions standards (nvPM).

    The standards of this section apply to an aircraft engine of Class 
TF, T3, or T8 with a rated output greater than 26.7 kN that is 
manufactured after January 1, 2023. Where a maximum nvPMMC 
standard is expressed as a formula, calculate and round the standard to 
the nearest 1.0 [mu]g/m\3\. Where an nvPMmass standard is 
expressed as a formula, calculate and round the standard to three 
significant figures or to the nearest 0.1 mg/kN. Where an 
nvPMnum standard is expressed as a formula, calculate and 
round the standard to three significant figures. Engines comply with an 
applicable standard if the test results show that the engine type 
certificate family's characteristic level does not exceed the numerical 
level of the nvPM standard when tested as described in subpart H of 
this part.
    (a) Except as provided in paragraph (b) or (c) of this section;
    (1) The characteristic level for the maximum nvPMMC 
expressed in units of [mu]g/m\3\ must not exceed the following:

nvPMMC = 10(3+2.9r0-0.274)


and
    (2) The characteristic level for nvPM mass expressed in [mg/kN] and 
for nvPM number expressed in [particles/kN] must not exceed the 
following:

                                           Table 1 to Paragraph (a)(2)
----------------------------------------------------------------------------------------------------------------
                                                                                          nvPMnum (particles/kN)
                Class                   Rated output (rO) (kN)      nvPMmass (mg/kN)
----------------------------------------------------------------------------------------------------------------
TF, T3, T8...........................  26.7 < rO <= 200.......  4646.9 - 21.497 (rO)...  2.669 x 10\16\ - 1.126
                                                                                          x 10\14\ (rO).
                                       rO > 200...............  347.5..................  4.170 x 10\15\.
----------------------------------------------------------------------------------------------------------------

    (b) For a change in type design by the type design holder, when the 
application for an amended type certificate is filed after January 1, 
2023:
    (1) If the engine qualifies as a derivative engine in accordance 
with Sec.  34.48 of this part, no testing is required for the engine to 
use the same nvPM certificated parameters (nvPMmass, 
nvPMnum, and maximum nvPMMC) as the engine it is 
derived from; or
    (2) If the engine does not qualify as a derivative engine in 
accordance with Sec.  34.48 of this part, the applicant must 
demonstrate compliance with each requirement in paragraph (a) of this 
section.
    (c) For issuance of an original type certificate when an 
application for type certification is filed after January 1, 2023, the 
applicant must demonstrate that the engine does not exceed:
    (1) For maximum nvPMMC: as prescribed in paragraph 
(a)(1) of this section; and
    (2) For the characteristic level for nvPMmass expressed 
in units of [mg/kN], and for nvPMnum expressed in units of 
[particles/kN], the following:

[[Page 31088]]



                                           Table 2 to Paragraph (c)(2)
----------------------------------------------------------------------------------------------------------------
                                                                                          nvPMnum (particles/kN)
                Class                   Rated output (rO) (kN)      nvPMmass (mg/kN)
----------------------------------------------------------------------------------------------------------------
TF, T3, T8...........................  26.7 < rO <= 150.......  1251.1 - 6.914 (rO)....  1.490 x 10\16\ - 8.080
                                                                                          x 10\13\ (rO).
                                       rO > 150...............  214.0..................  2.780 x 10\15\.
----------------------------------------------------------------------------------------------------------------


0
12. Amend Sec.  34.48 by revising paragraph (a) introductory text and 
paragraph (b) to read as follows:


Sec.  34.48  Derivative engines for emissions certification purposes.

    (a) General. A type certificate holder may request from the FAA a 
determination that an engine configuration is considered a derivative 
engine for emissions certification purposes (all gaseous emissions and 
either nvPM or smoke number as applicable). To be considered a 
derivative engine for emissions certification purposes under this part, 
the configuration must have been derived from the original engine that 
was certificated to the requirements of part 33 of this chapter and one 
of the following:
* * * * *
    (b) Emission similarity (1) The type certificate holder must 
demonstrate that the proposed derivative engine model's emissions meet 
the applicable standards and differ from the original model's emission 
rates within the following ranges and values:
    (i) 3.0 g/kN for NOX.
    (ii) 1.0 g/kN for HC.
    (iii) 5.0 g/kN for CO.
    (iv) 2.0 SN for smoke (where applicable).
    (v) The following values apply for maximum nvPMMC, 
nvPMmass, and nvPMnum (where applicable):
    (A) maximum nvPMMC:
    (1) 200 [mu]g/m3 if the characteristic level of maximum 
nvPMMC is below 1,000 [mu]g/m\3\; or
    (2) 20% of the characteristic level if the 
characteristic level for maximum nvPMMC is at or above 1,000 
[mu]g/m\3\.
    (B) nvPMmass:
    (1) 80 mg/kN if the characteristic level for nvPMmass 
emissions is below 400 mg/kN; or
    (2) 20% of the characteristic level if the 
characteristic level for nvPMmass emissions is greater than 
or equal to 400 mg/kN.
    (C) nvPMnum:
    (1) 4 x 10\14\ particles/kN if the characteristic level for 
nvPMnum emissions is below 2x10\15\ particles/kN; or
    (2) 20% of the characteristic level if the 
characteristic level for nvPMnum emissions is greater than 
or equal to 2 x 10\15\ particles/kN.
    (2) If the characteristic level of the original certificated engine 
model (or any other sub-models within the emission type certificate 
family tested for certification) before modification is at or above 95% 
of the applicable standard for any pollutant, an applicant must measure 
the proposed derivative engine model's emissions for all pollutants to 
demonstrate that the derivative engine's resulting characteristic 
levels will not exceed the applicable emission standards. If the 
characteristic levels of the originally certificated engine model (and 
all other sub-models within the emission type certificate family tested 
for certification) are below 95% of the applicable standard for each 
pollutant, the applicant may use engineering analysis consistent with 
good engineering judgment to demonstrate that the derivative engine 
will not exceed the applicable emission standards. The engineering 
analysis must address all modifications from the original engine, 
including those approved for previous derivative engines.
    (3) In unusual circumstances and consistent with good engineering 
judgement, the FAA may adjust the ranges specified in paragraph (b)(1) 
of this section to evaluate a proposed derivative engine.
* * * * *

0
13. Amend Sec.  34.60 by revising paragraph (h) to read as follows:


Sec.  34.60  Introduction.

* * * * *
    (h) The system and procedure for sampling and measurement of 
gaseous emissions shall be as specified by in Appendices 2, 3, 4, 5 and 
6 to the International Civil Aviation Organization (ICAO) Annex 16, 
Environmental Protection, Volume II, Aircraft Engine Emissions, Third 
Edition, July 2008 (incorporated by reference, see Sec.  34.4).

0
14. Add subpart H to read as follows:
Subpart H--Test Procedures and Compliance Demonstration for Non-
Volatile Particulate Matter Emissions
34.71 Non-Volatile Particulate Matter (nvPM) Test Procedures.
34.73 Demonstration of compliance for nvPM emissions.

Subpart H--Test Procedures and Compliance Demonstration for Non-
Volatile Particulate Matter Emissions


Sec.  34.71  Non-volatile particulate matter (nvPM) test procedures.

    For each Class TF, T3, or T8 engine manufactured after January 1, 
2023, that has a rated output greater than 26.7 kN, the test procedures 
for measuring each required nvPM parameter are as follows:
    (a) Measure the emissions of all nvPM parameters required in this 
part, as applicable.
    (b) Collect data from at least three engine tests, with each test 
conducted at the reference LTO time/thrust combinations shown in 
paragraph (h) of this section.
    (c) For the engines referenced in paragraph (b) of this section, 
all emissions certification tests may be conducted on one or more 
engines of the same type design.
    (d) Use a test fuel that meets the specifications described in 
Appendix 4 of ICAO Annex 16, Volume II (incorporated by reference, see 
Sec.  34.4). The test fuel must not have any additive whose purpose is 
to suppress nvPM emissions.
    (e) (1) When conducting test measurements in accordance with 
paragraphs (a) through (c) of this section, use the equipment and 
procedures specified in Appendix 1, Appendix 4, Appendix 6, and 
Appendix 7 of ICAO Annex 16, Volume II (incorporated by reference, see 
Sec.  34.4), when demonstrating whether an engine meets the applicable 
nvPM limit specified in Sec.  34.25 of this part.
    (2) An applicant that seeks to use a procedure or equipment that 
differs from any specified in this part must request FAA approval in 
writing with supporting justification before the alternative procedure 
or equipment may be used to demonstrate compliance. The FAA will 
consult with the EPA on any such request. The FAA may approve the 
requested alternative for measuring nvPM, including testing and 
sampling methods, analytical techniques, and equipment specifications. 
Each request must meet one of the following conditions:

[[Page 31089]]

    (i) The engine cannot be tested using a specified procedure; or
    (ii) The alternative procedure is shown to be equivalent to, or 
more accurate or precise than, the specified procedure.
    (f) Any engine accessory included in a type design that may 
reasonably be expected to influence either nvPM emissions or 
measurements must be installed on the engine before testing. The test 
engine must not extract shaft power or bleed service air to provide 
power to auxiliary gearbox-mounted components necessary to drive 
aircraft systems;
    (g) For each percentage of rated output thrust level prescribed in 
paragraph (h) of this section, a test engine must reach and maintain a 
steady operating condition before any nvPM emission measurement is 
made;
    (h) The following landing and takeoff (LTO) cycles apply for nvPM 
emissions testing and for calculating weighted LTO values:

                        Table 1 to Paragraph (h)
------------------------------------------------------------------------
                                                     Class TF, T3, T8
                      Mode                       -----------------------
                                                   TIM (min)    % of rO
------------------------------------------------------------------------
Taxi/idle.......................................        26.0           7
Takeoff.........................................         0.7         100
Climbout........................................         2.2          85
Descent.........................................          NA          NA
Approach........................................         4.0          30
------------------------------------------------------------------------

    (i) An engine complies with an applicable limit if the test results 
show that the engine type certificate family's characteristic level 
does not exceed any limit for maximum nvPMMC, 
nvPMnum, and nvPMmass described in Sec.  34.25.
    (j) All measurements collected during engine tests required in 
paragraph (b) of this section must be used in the calculation of nvPM. 
Before any calculations are made, the FAA must approve the exclusion of 
any measurements that the applicant seeks to exclude, including any 
justification for such exclusions.
    (k) The system and procedure for sampling and measurement of 
gaseous emissions shall be as specified by Appendices 1, 4, 6, and 7 of 
ICAO Annex 16, Volume II (incorporated by reference, see Sec.  34.4).


Sec.  34.73  Demonstration of compliance for nvPM emissions.

    (a) Each compliance demonstration by an applicant requires:
    (1) Establishing a mean value from tests conducted on one or more 
engines;
    (2) Calculating a ``characteristic level'' by applying a set of 
statistical factors that take into account the number of engines tested 
in accordance with Sec.  34.71(b) of this part; and
    (3) Rounding each characteristic level to the same number of 
decimal places as the corresponding emission limit.
    (b) In demonstrating compliance with this subpart, an applicant 
must use the nvPM measurements collected in accordance with Sec.  34.71 
as follows:
    (1) An engine complies with an applicable standard when the engine 
type certificate family's characteristic level does not exceed any nvPM 
limit described in Sec.  34.25 of this part; and
    (2) A compliance demonstration consists of:
    (i) Determining the maximum nvPMMC, and the mean value 
for nvPMmass and nvPMnum from the data collected 
in accordance with paragraph Sec.  34.71(f) of this part;
    (ii) Correcting each data point to standard temperature and 
pressure conditions;
    (iii) Applying the appropriate statistical factor shown in Table 6-
1 of Appendix 6 of ICAO Annex 16, Volume II (incorporated by reference, 
see Sec.  34.4) to account for the number of engines tested; and
    (iv) Rounding each characteristic level to the same number of 
decimal places as the corresponding nvPM limit in Sec.  34.25 of this 
part.
    (c) (1) In determining maximum nvPMMC, an applicant must 
use one of the following evaluation methods for all engines measured in 
accordance with Sec.  34.71(c) of this par and using the thrust 
settings given in Sec.  34.71(h) of this part. An applicant may choose 
to measure additional thrust settings; while there is no restriction on 
the number of thrust settings measured, the same thrust settings must 
be used on each engine tested. A dataset consists of nvPMMC 
measurements made at each thrust setting across the thrust range chosen 
by the applicant for each engine. Plot all nvPMMC 
measurements versus thrust setting.
    (i) Method 1--
    (A) Average the individual data points measured at each thrust 
setting to develop one dataset of nvPM mass concentration for each 
engine tested, creating an average dataset for each engine; and
    (B) Use the averages generated in paragraph (c)(1) of this section 
to develop a single curve fit to determine the overall maximum 
nvPMMC value;
    (ii) Method 2--
    (A) Measure individual data points of nvPMMC versus 
thrust. Using all datasets generated for each engine physically tested, 
develop a single, separate curve fit;
    (B) Determine the maximum nvPMMC from each engine curve 
fit resulting from paragraph (c)(1) of this section; and
    (C) If more than one engine is physically tested, average the 
nvPMMC values from paragraph (c)(2) of this section to 
determine the overall maximum nvPMMC value for the model 
tested; or
    (iii) Method 3--
    (A) Develop a curve fit of nvPMMC versus thrust for each 
test conducted on each engine physically tested;
    (B) From each curve fit developed in paragraph (c)(1) of this 
section, use the resultant curve fit equation to solve for each 
maximum;
    (C) Average the maximum values for each engine physically tested; 
and
    (D) Average the maximum values determined in paragraph 
(c)(1)(iii)(C) of this section to determine the overall average maximum 
nvPMMC value.
    (2) Using the data measured in Sec.  34.71(b) of this part, 
determine the nvPM characteristic levels for nvPMnum and 
nvPMmass as follows:
    (i) Average all nvPMnum and nvPMmass 
measurements in units of number of particles per kN or mg per kN, as 
applicable, from each emissions test at each percentage of rated output 
thrust setting;
    (ii) Multiply the averaged measurement from paragraph (a)(2)(i) of 
this section by the appropriate time in mode (TIM) as shown in Sec.  
34.71(h);
    (iii) Sum the products from paragraph (a)(2)(ii) of this section to 
determine the LTO values for nvPMnum and 
nvPMmass; and
    (iv) Divide the result of paragraph (a)(2)(iii) of this section by 
the characteristic level factor, shown in Table A6-1 of Appendix 6 of 
ICAO Annex 16, Volume II (incorporated by reference, see Sec.  34.4), 
for the number of engines physically tested to determine the 
nvPMmass and nvPMnum characteristic values.
    (d) The data used to determine the regressed curves must meet a 90% 
confidence interval, CI90, limit of 1.5% of each 
nvPM limit specified in Sec.  34.25 of this part. If a certification 
test fails to meet the CI90 limit, the engine type may still 
comply with the requirements. Failure may be caused by excessive data 
scatter, too few data points, or erroneous data used to regress an 
accurate curve. Without deleting or removing any prior measurement 
data, additional data acquired from further tests may improve the 
CI90 by adding to the sample population.
    (e) The following information must be reported to the FAA 
substantiating

[[Page 31090]]

compliance with nvPM limits of Sec.  34.25 of this part:
    (1) The values of nvPM emissions measured and computed in 
accordance with the procedures and calculated as required by this 
subpart in Sec.  34.71 of this part and paragraphs (a) through (d) of 
this section;
    (2) For each engine tested:
    (i) Engine model, series, and serial number;
    (ii) Rated thrust (kN);
    (iii) Overall pressure ratio;
    (iv) The methods of data acquisition; and
    (v) The method of data analysis chosen by the applicant under 
paragraphs (a) through (d) of this section.
    (3) Demonstration that the fuel used for each test is in compliance 
with the fuel specification listed in Appendix 4 of ICAO Annex 16, 
Volume II (incorporated by reference, see Sec.  34.4). For the fuel 
used for nvPM emissions certification, include the following fuel 
characteristics:
    (i) Hydrogen/carbon ratio;
    (ii) Net heat of combustion (MJ/kg);
    (iii) Hydrogen content (mass per cent);
    (iv) Total aromatics content (volume per cent);
    (v) Naphthalene content (volume per cent); and
    (vi) Sulfur content (ppm by mass).
    (4) For each engine tested for certification purposes, the 
following values measured and computed in accordance with the 
procedures of Sec.  34.71 of this part:
    (i) Fuel flow (kg/s) at each thrust setting of the LTO cycle;
    (ii) nvPM EImass (mg/kg of fuel) at each thrust setting 
of the LTO cycle;
    (iii) nvPM mass emission rate [nvPM EImass x fuel flow] 
in mg/s;
    (iv) nvPM EInum (particles/kg of fuel) at each thrust 
setting of the LTO cycle;
    (v) nvPM number emission rate [nvPM EInum x fuel flow] 
in particles/s;
    (vi) Total gross emissions of nvPM mass measured over the LTO cycle 
in mg;
    (vii) Total gross emissions of nvPM number measured over the LTO 
cycle in particles;
    (viii) LTO nvPMmass/thrust in mg/kN;
    (ix) LTO nvPMnum/thrust in particles/kN; and
    (x) Maximum nvPMMC in [micro]g/m\3\; and
    (5) For each engine tested for certification purposes, the 
characteristic levels for the maximum nvPMMC, the LTO 
nvPMmass/thrust, and the LTO nvPMnum/thrust.

    Issued under authority provided in 42 U.S.C 4321 et seq., 7572, 
49 U.S.C. 106(f), 40113, 44701-44702, 44703, and 44704, in 
Washington, DC.
Michael G. Whitaker,
Administrator.
[FR Doc. 2024-08453 Filed 4-23-24; 8:45 am]
BILLING CODE 4910-13-P